Consider the Earth and a cloud layer 800m above the planet to bethe platesof a parallel-plate capacitor.
a)If the cloud layerhas an area of 1.0 km2=1.0x106m2, what is the capacitance?
b) If an electricfield strength greater3.0x106 N/C causes air to breakdownand conduct charge (lightning), what is the maximum charge the cloud can hold?